Narrative boundaries: Can ghosts be real (in fiction)?

First of all - as if to prove my point that I confuse Edith Wharton and Willa Cather - I managed to do just that in yesterday's post. Wharton wrote the story "Afterward," which is about a couple that rents a Tudor mansion in Dorset and the husband is haunted by a man he'd ruined in business. I should have known this, as the story is the far more Jamesian of the two (Wharton and James were close). Cather wrote "Consequences," about a man who is pursued by a ghost and hounded into suicide. Story set in NYC among clubbish professional men seems atypical of Cather, and not a great story. The next story in the Library of America "American Fantastic Tales," by Ellen Glasgow, called The Distant (?) Third, is a good contrast with the preceding set of "cool" ghost stories (the ghost vision validated by someone perfectly sane). In this one, only the "good" people can see the ghost - image of a young girl who has apparently died. This is a pretty sophisticated story, playing along the edges of pscyhological thriller and fantasy/horror and exploring the boundaries of narration: how are we to determine which vision is "real"? Does the ghost exist? Or are those who see it delusional? Story is: a woman's husband, a prominent doctor (Dr. Maradick), hires the narrratror to be the night nurse for his wife, who, he believes, is mentally ill. He (and others) claim her daughter has died; she (and the narrator!) see the young girl from time to time. Eventually, the woman sent away to an asylum, where she dies - but the narrator continues to see the ghost of the girl, and she speaks up to the powerful doctor - which apparently ruins her future as a nurse. Once again, the influence of Turn of the Screw is strong - bringing children into ghost stories is a great device that has become a staple of a lot of films. (Note: Am also posting today on the film of "The Girl with the Dragon Tattoo" on my other blog, elliotswatching.blogspot.com)